Visual landing aid for airplanes



June 22, R' F. MITCHELL 3,19l,l46

vSUAL LANDING AD FOR ARPLANES Fed March 26 1962 2 Sheetssheet 2 Mirror FIG.|O 

1. AN AIRPLANE VISUAL LANDING AID DEVICE CONSISTING OF AN ESSENTIALLY LIGHT TIGHT CASE CONTAINING A LENS AT ONE END AND TWO LAMP UNITS AT THE OTHER, SAID LAMP UNITS CONSISTING OF LINE FILAMENT TYPE LAMPS ARRANGED HORIZONTALLY AND PARALLEL TO SAID LENS AND ALSO PARALLEL TO THE OPTICAL AXIS OF SAID DEVICE, ONE SAID LAMP UNIT BEING SET BELOW SAID AXIS AND ONE LAMP UNIT ABOVE SAID AXIS, WITH BOTH BEING SET INSIDE THE NORMAL FOCAL POINT OF SAID LENS SO THAT TWO VIRTUAL IMAGES APPEARING AS LINES OF LIGHT WILL BE FORMED A SUBSTANTIAL DISTANCE BACK OF SAID DEVICE, WITH SAID OPTICAL AXIS SET AT AN ANGLE TO THE RUNWAY EQUIVALENT TO THE DESIRED GLIDE SLOPE APPROACH ANGLE, WITH SPECIAL COLOR FILTERS SET BETWEEN SAID LAMP UNITS AND SAID LENS IN SUCH A WAY THAT A PILOT APPROACHING FOR A LANDING AT TOO 